In China,dòu fu is a kind of food with rich nutrition and a long history. The popularity of dòu fu promotes the development of its production technology. The first production process of dòu fu is pulping, which is about to make soybean milk. The second is the solidification process, that is, soybean milk coagulating into a gel containing plenty of water under the combined action of heat and coagulant. That is dòu fu.